1. Field of the Invention
The present invention broadly relates to the art of etching, and more particularly to the art of etching to provide mirrors having window areas of discrete pre-determined configuration incorporated therein, which may be backed by an ornamental layer having design areas corresponding and juxtaposed to said window areas.
2. Description of the Prior Art
Etching of glass and other materials to provide ornamental articles is well-known in the art. Various means of producing images in glassware and metals have been utilized, the variations thereof depending upon the particular workpiece, the design or ornamentation desired to be incorporated therein and the effect desired to be created. There are, however, certain steps which are common to many of those processes.
Frederecici, U.S. Pat. No. 154,032, Bradley, U.S. Pat. No. 243,200, Stern, U.S. Pat. No. 322,864, Paini, U.S. Pat. No. 343,889, Freidrich, U.S. Pat. No. 1,205,728, Kueffel et al., U.S. Pat. No. 2,374,356, Maleyre, U.S. Pat. No. 2,530,436 and Becca et al., U.S. Pat. No. 3,759,753, all involve, in one form or another, means of delineating an image upon a surface, such as the utilization of stenciling or other means of patterning a design upon an object, applying a protective resist substance and etching. Each also teaches removing the protective resist material following etching.
Other well-known methods include the use of photo-resist materials, processed either in the positive or negative mode, to delineate the desired image. Examples are found in Spitzer, U.S. Pat. No. 865,276, Ross, U.S. Pat. No. 2,094,432, Van Natter, U.S. Pat. No. 3,205,155 and Mesley, U.S. Pat. No. 3,642,476. Of the above, only Spitzer does not mention the removal of the photo-resist material.
Colbert et al., U.S. Pat. No. 1,942,686, discloses a process for producing an ornamental mirror wherein the reflective metallic coating of the mirror is first completely covered by a protective copper coating. Removal of the copper and silver by etching is accomplished subsequent to a photo-resist cold top enamel process. Two protective layers, the copper and the reflective layer, especially if a silkscreening method is utilized to achieve the desired design, as exemplified in the Colbert patent.
A further patent illustrating a method of making a transparent area in a mirror is Cheney, U.S. Pat. No. 2,036,021, wherein a protective coating, capable of removal, is placed completely over the reflective backing of the glass. Photosensitive material is utilized to create the desired ornamentation and thereafter the protective coating, exposed by the washing away of the soluble photosensitive material, is removed to expose the reflective metallic area for etching.
Also of interest are references disclosing various methods and devices for distributing the etching solution over the workpiece, such as U.S. Pat. No. 1,081,290 and U.S. Pat. No. 1,313,233. These patents illustrate the use of gas to agitate the etching solution, a procedure quite different from that embraced by the present invention.
One final reference, of only peripheral interest, is Souliner, U.S. Pat. No. 2,684,892 which teaches the use of particular etching compositions.
None of these references, however, either alone or in combination, even suggests the invention herein disclosed.